Prevention of bacterial endocarditis - Recommendations by the American Heart Association
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
Prevention of bacterial endocarditis
Recommendations by the American Heart Association
Authors Dajani A, Taubert K, Wilson W, Bolger A, Bayer A, Ferrieri P, Gewitz M, et al.
Source JAMA. 277:1794-1801. June 11, 1997.
Institutions American Heart Association; American Dental Association; Infectious Diseases
Society of America; American Academy of Pediatrics; American Society of
Gastrointestinal Endoscopy.
Support American Heart Association.
Background
Bacterial endocarditis is a potentially life-threatening condition. It results from infection of
susceptible (usually previously abnormal) cardiac structures resulting from bacteremia. A
number of diagnostic and therapeutic procedures can cause transient bacteremia. Antibiotic
prophylaxis at the time of these procedures may thus be able to prevent endocarditis. Although
this approach is plausible and has been validated in some animal models, controlled clinical
trials in humans have not been performed and are unlikely to be undertaken. In the absence of
such trials, recommendations such as those presented here must be based on extensive review
of the available evidence. This paper is an update of the AHA committee's 1990
recommendations.
Approach
The presumed benefit of antibiotic prophylaxis depends on the cardiac abnormality for which
prophylaxis is being considered and the procedure causing bacteremia. Certain cardiac
conditions are more susceptible to endocarditis than others; furthermore, established
endocarditis is more dangerous in certain settings (such as prosthetic valves) than others. Both
the risk of bacteremia and the likely organisms vary according to the procedure being
performed; some organisms are more likely to cause endocarditis than others.
As a result, the decision whether or not to prophylax and the choice of antibiotics will depend
both on the cardiac abnormality and on the procedure (as well as on certain other patient-
specific factors).
Cardiac conditions
Cardiac conditions are classified into high, moderate and negligible risk. The latter category is
felt not to require prophylaxis. The principal differences between the high and moderate risk
categories lie in the antibiotic regimens recommended for GI and GU procedures, and in
whether or not prophylaxis is needed for certain lower-risk procedures.
Negligible risk
These cardiac conditions are felt not to require prophylaxis.Isolated ostium secundum ASD and surgically repaired ASD, VSD and PDA
(beyond 6 months and without sequelae).
Mitral valve prolapse without mitral regurgitation and without thickened leaflets.
Innocent or physiologic murmurs (echo required in the adult population to rule out
valvular lesion).
Cardiac pacemakers and defibrillators.
History of isolated bypass surgery, history of Kawasaki disease without valvular
dysfunction and history of rheumatic fever without valvular dysfunction.
High risk
These conditions are:
All prosthetic heart valves (including bioprostheses and homografts).
Any history of previous bacterial endocarditis.
Complex cyanotic congenital heart disease and surgically constructed systemic
pulmonary shunts.
Moderate risk
Most cardiac conditions requiring prophylaxis will fall into this category.
Congenital cardiac malformations, not falling into the high or negligible risk
categories (such as PDA, VSD, ostium primum ASD, bicuspid aortic valve and
coarctation).
Acquired valvular heart disease (such as rheumatic heart disease, valvular stenosis
and regurgitation).
MVP with regurgitation and/or myxomatous leaflets.
Hypertrophic cardiomyopathy.
In the article text is a more detailed description of the issue of mitral valve prolapse,
including the significance of valve morphology and audible clicks. The only patients
with MVP who are not recommended for prophylaxis are those patients with isolated
prolapse, normal appearing leaflets, no doppler evidence of regurgitation and no
murmurs (with maneuvers). Patients with MVP and only a systolic click represent a
controversial subset and warrant either prophylaxis or a very vigilant search for
intermittent regurgitation (doppler and auscultation with maneuvers). The importance of
MVP as an etiology for endocarditis in the pediatric age group is stressed. See text for
more details.
Principal recommendations
Procedures requiring prophylaxis
Prophylaxis
Procedures
recommendationsDental and oral procedures
Dental procedures with bleeding:
Prophylaxis
extractions recommended
cleaning In addition, consider
periodontal procedures antiseptic rinse
dental implant placement immediately prior to
endodontic surgery (root canal) procedure
initial placement of orthodontic bands
intraligamentary local anesthesia
Dental procedures unlikely to cause bleeding:
Not recommended
Restorative dentistry (including cavity filling)
Nonintraligamentary local anesthesia If unanticipated
Intracanal endodontic treatment post-placement bleeding, consider
Suture removal antibiotic prophylaxis
Placement and adjustment of orthodontic and prosthodontic
within 2 hours
devices
Respiratory tract
Surgical operations involving respiratory mucosa, including
tonsillectomy/adenoidectomy Recommended
Bronchoscopy with rigid bronchoscope
High risk patients:
Optional
Flexible bronchoscopy, with or without biopsy
Others: not
recommended
Endotracheal intubation
Not recommended
Tympanostomy tube insertion
Gastrointestinal tract
High risk:
Esophageal sclerotherapy and dilatation
recommended
ERCP in the presence of obstruction and biliary tract surgery
Moderate risk:
Surgery involving the intestinal mucosa
optional
High risk: optional
Endoscopy, with or without biopsy
Others: not
Transesophageal echocardiography
recommended
Genito-urinary tract
Prostate surgery
Urethral dilatation Recommended
Cystoscopy
In case of infection,
culture guided
In the presence of infection: therapy (until
Urethral catheterization sterilization, when
Uterine D&C; therapeutic abortion; sterilization; insertion or possible)
removal of IUDHigh risk: optional
Vaginal hysterectomy
Others: not
Vaginal delivery
recommended
Caesarean section
In uninfected tissue:
Not recommended
Urethral catheterization
Uterine D&C; therapeutic abortion; sterilization; insertion or
removal of IUD
Antibiotic regimens
In the following, prophylactic regimens for adults are listed. For dosages in the pediatric
population, please refer to the article.
Procedure
Prophylactic regimen recommended
and situation
Dental, oral, respiratory tract and esophageal procedures
Standard
Amoxicillin 2.0 g orally one hour before procedure
regimen
Unable to take
Ampicillin 2.0 g IM or IV, within 30 minutes before procedure
orally
Clindamycin 600 mg or
Azithromycin 500 mg or
Clarithromycin 500 mg or
Penicillin
for patients who have not had an immediate local or systemic reaction to a
allergic
pencillin (urticaria, angioedema or anaphylaxis) and who can tolerate first
generation cephalosporins: Cephalexin or Cefadroxil 2.0 g
orally, 1 h before procedure
Pencillin Clindamycin 600 mg IV or
allergic and Cefazolin 1.0 g IM or IV (for patients who can tolerate, see above)
unable to take
orally within 30 minutes before procedure
Genitourinary and gastrointestinal (not esophageal) procedures
Ampicillin 2.0 g IV or IM plus gentamycin 1.5 mg/kg (up to 120 mg)
High risk within 30 min of starting procedure
patients
followed by ampicillin 1.0 g IV/IM or amoxicillin 1 g orally 6 hours later
High risk
patients Vancomycin 1.0 g IV over 1-2 h plus gentamycin 1.5 mg/kg IV/IM (up to
allergic to 120 mg) to be completed within 30 min of starting procedure
ampicillinModerate risk Amoxicillin 2.0 g orally 1 h before procedure or ampicillin 2.0 g IM/IV
patients within 30 min of starting procedure
Moderate risk
patients Vancomycin 1.0 g IV over 1-2 hr, to be completed within 30 min of
allergic to starting procedure
ampicillin
It should be noted that the current recommendations do not include an erythromycin-based
regimen for oral prophylaxis, because of problems with pharmacokinetics and gastro-intestinal
tolerability. The authors note, however, that patients who previously used erythromycin for
endocarditis prophylaxis and who tolerated it at the recommended doses can continue to do
so.
Specific situations
Patients already taking antibiotics for another reason (particularly pencillin for rheumatic
fever prophylaxis) should be given an agent from a different class for endocarditis
prophylaxis.
Patients at risk for endocarditis who undergo surgical procedures involving infected tissue
should have antibiotic prophylaxis directed at the most likely pathogens.
Patients at risk for endocarditis who undergo open heart surgery should have prophylaxis
directed primarily at staphylococci (with an agent appropriate to the hospital's antibiotic
susceptibility pattern). Cardiac transplant recipients should probably be considered at moderate
risk for endocarditis and receive prophylaxis accordingly.
Comment
As in the past, these recommendations are based not on controlled clinical trials (which are unlikely
to be carried out) but on best-available evidence and consensus. Nevertheless, they are important
both because of the strength of the indirect evidence upon which they are based and for medico-
legal reasons (they will rapidly become standard-of-care).
The lower dose of amoxicillin and the lack of a second dose 6 hours post-procedure for oral
regimens is a substantial change from the previous recommendations. The lack of an erythromycin
regimen for oral procedures is another substantial change.
The exact significance of "optional" prophylaxis in some of the situations noted above is not
entirely clear. Prudence will probably dictate recommending prophylaxis in most of them. As
always, these recommendations are meant to be interpreted with the individual patient in mind. The
article text contains much interesting and valuable material that was not summarized here; I
strongly recommend reading it at least once.
August 1, 1997
References
References related to this article from the NLM's PubMed database.Reader Comments
October 23, 1997
Letters to the editor concerning this article appeared in the October 15 issue of JAMA. These
letters concern clarification of the need for prophylaxis with dermatologic procedures, traumatic
lacerations and mitral valve prolapse without an audible murmur.
Date: Sat, 17 Feb
From: "Dr. Chew"
In the recommendations regarding urological procedures, it is not clear whether changing of long
term urinary catheter requires antibiotic prophylaxis. We know that prolonged catheterization
increases the chances of bacteriuria and thus, should we consider changing catheters the same as
catheterizing an infected bladder?
In a recent issue of Arch. Int. Med, there is a study on whether changing urinary catheter in the
elderly who are on catheter for long term results in bacteraemia. It seems that not the usual gram
negative bacteria are found but coagulase negative Staphylococcus, and the authors think that the
risk of bacteraemia is low. However, they suggested that antibiotic prophylaxis needs to be
seriously considered if prostheses like hip prostheses are present. The authors also identified
mucosal breaks as a risk factor for bacteraemia.
Another point is that replacing erythromycin with a newer macrolide may not be necessary unless
the organisms present in the community are well known to be resistant to erythromycin. Switching
to a newer macrolide increases the cost of antibiotic prophylaxis and this may not be a good idea in
the developing world where infective endocarditis is fairly common.
The Archives study you mention looked at 480 blood cultures drawn during 120 catheter
changes in 39 patients with indwelling urinary catheters. The authors found an incidence of
bacteremia resulting from the procedure in about 4% of catheter changes. None of these
bacteremias led to clinical incidents, but we do not know how many patients had valvular
heart disease or prostheses. Interestingly, a significant number of the bacteremias were
caused by coagulase negative staphylococci, which were not cultured from the urine, but
which were often cultured from the catheter itself.
It would certainly seem prudent to treat indwelling catheter changes as equivalent to
catheterizing infected urine, particularly in the presence of a prosthetic heart valve. Whether
the antibiotic regimen chosen should reflect the possibility of coagulase negative
staphylococcal bacteremia is unclear to me.
As noted in the summary, the reason erythromycin is no longer recommended is because of
GI intolerance and erratic bioavailability, not because of susceptibility patterns. Thus, if it is
preferable from an economic standpoint, it can still be used. --mj
Submit a commentJournal Club homepage
You can also read
